Tutorial 6: 14th November 2019

Question 1

What were the key points of the road to SDN paper?

Answer 1

Programmable networks initially thought of with active networking theory, then trying to separate the data and control planes to make network management easier and improve methods of routing network traffic. OpenFlow is a balance between the two.

OpenFlow can be implemented on existing switch chipsets, so it is backwards-compatible.

SDN technologies will live or die based on “use pulls”.

OpenFlow development prioritising rapid adoption now and feature depth later; want backwards-compatibility.

Need to find a balance between adding the features we want (including long-term maintainability and modularity) and allowing rapid adoption now with backwards-compatibility.

Question 2

What is BGP?

Answer 2

BGP (Border Gateway Protocol) is protocol that manages how packets are routed across the internet through the exchange of routing and reachability information between edge routers. BGP directs packets between autonomous systems (AS) – networks managed by a single enterprise or service provider.

Question 3

Can you use BGP between ISPs now?

Answer 3

yes

Question 4

Does SDN implement new networking functionality?

Answer 4

No.

Question 5

Why is SDN useful if it doesn’t let us do more with networks?

Answer 5

It allows functions currently done manually by people to be done automatically and for the abstraction and modularity of functionality.